Ribbon mechanism



June 13, 1939. R. c. COXHEAD 2,161,856

RIBBON MECHANISM I Filed April 28, 1937 5 sheets-sheet 1,

14 will] INYEXTOR. I 3 m 0/1716 0?! W, la -a, 6AM, -f L 1m ATTORNEY RIBBON MECHANISM Filed April 28, 1937 5 SheLs-Sheef 2 (/M K lm/m/ Wm M 5 Sheets-Sheet 3 C m .9 m? M v m. W ,n w W -9 WW I r A 1 ,z i mi 0 M m f fl m fl [M1 1 z 8 W? n M June 13, 1939. R. c. coxHEAD RIBBON MECHANISM Filed April 28, 1957 June 13, 1939. R c, CQXHEAD V 2,161,856

RIBBON MECHANISM Filed April 28, 1937 5 Sheets-Sheet 4 INVENTOR.

. fii? 4M4 ATTORNEY Jun 13, 1939.

R. C. COXHEAD RIBBON MECHANISM 5 Sheets-Sheet 5 Filed April 28, 1937 Patented June 13, 1939 UNITED STATES RIBBON MECHANISM Ralph C. Coxhead, New York, N. 1., assignor to 1 Ralph C. Ooxhead Corporation, New York, N. Y., a corporation of Delaware Application April 28,

' 9 Claims.

The present invention relates broadly to typewriters and more especially to aribbon mechanism which is adaptable not only'for typewriters but for other printing devices which-use ribbons such as calculating machines, check printers, etc.

The present invention is disclosed more especially with reference to a typewriting machine known in'the art as the Vari-Typer but it is useful in connection with other types of machines.

The particular embodiment disclosed is a construction in the form of an attachment to a normal ribbon mechanism whereby a special ribbon may be utilized for special kinds of work.

One of the principal features of the present invention is a narrow width paper ribbon carrying a pigment, and which is operated under control of mechanisms in such manner that the printing occurs in substantially'the mid portion only of the ribbon that is fed through the mechanism once and then discarded.

A further feature of the invention relates to the feed mechanism of the ribbon which is so controlled as to advance the ribbon one type character space after each printing operation so that an entire unused spot in the ri bon is available at the printing point whereby e ch imprint from a type character comprises an unused part of the ribbon.

A further feature of the invention, in its more specific embodiment, comprises a ribbon feed constructed to feed the ribbon variable amounts depending upon the width of the type faces of the type characters. The "Vari-Typer typewriter is provided with changeable fonts of type which may vary in size as well as in design and the ribbon feed mechanism is adjustable to properly feed the ribbon with relation to the particular font of type in use.

A still further feature of the present invention comprises constructions whereby the ribbon feed is controlled with reference to the printing instrumentalities so that the operation of a space bar which feeds the carriage without printing does not result in a ribbon feed operation.

A further feature of the present invention reev sides in constructions which are detachable and which cooperate with normal ribbon feed mechanism usually employed with textile ribbons so that by simple manipulation and changes of re- 50 movable parts, the machine may be quickly changed from a textile type ribbon of normal use to the special narrow width paper ribbon for special use. Y

The present invention while adapted for varis5 ous purposes is particularly useful in connection 1937, Serial Nb. 139,425

with the production of master sheets of printin adapted for reproduction by lithographic processes for publication. In this type of work, it is particularly desirable that the typewritten or printed master sheet shall be composed of printed characters of uniform density and without the ribbon pattern appearing on the characters as is the situation where textile ribbons are used for printing the characters on the master sheet. In

order to obtain the desired results, it has been found that carbon paper or other pigmentized operation so that type imprints on the ribbon may I overlap and, furthermore, the ordinary textile ribbon is of double width so that there are two zones on the ribbon adjacent each edge thereof for printing operations, It has been found that where wide paper ribbons have been used, the pounding of the type against the paper strip tends to stretch the portion under impact so that double width paper ribbon is unsatisfactory because one side becomes longer than the other and hence tends to wrinkle and thus interferes with its proper functioning of the ribbon. The use of a narrow paper ribbon on which the impressions are made in the center of the 'ribbon obviates the difiiculty and since the ribbon is used but once and discarded, the danger of uneven printing dueto a prior use of the ribbon is entirely avoided.

Another important feature of the present invention is that the narrow ribbon is fed positively and definitely for each operation of the ribbon feed. The ordinary ribbon mechanism operates by unwinding the ribbon from a supply spool and winding it upon a receiving spool. As the receiv ing spool increases in diameter, during the ribbon feed operation, the amount ofribbon feed varies, since ordinarilythe receiving spool receives uniform angular movements for each ribbon feed operation. According to the present invention, the

ribbon is fed between a pair of positive feed rolls It is realized that the present invention may be embodied in structures other than those specifically disclosed herewith, and, therefore, this dis- 10 Fig. 4 is an upright sectional detail view taken on line 4 -4 of Fig. 3.

Fig. 5 is a detailed sectional view taken on line 5-5 of Fig. 4 and illustrating a portion of the ribbon feed mechanism by which the feed may 15 be varied.

Fig. 6 is a view similar toFig. 5 and in which the ribbon feed mechanism is shown as bein adapted to be adjusted to vary the amount of ribbon feed.

20 Fig. 7 is a detail view illustrating the effective operation of the ribbon feed driving mechanism to advance the ribbon for a small amount of ribbon feed.

Fig. 8 is a view similar to Fig. 7 illustrating N the parts arranged for a larger amount of ribbon feed.

Fig. 9 is a view similar to Figs. 7 and 8 in which the parts have been controlled by the space bar to prevent feeding of the ribbon when the space bar is operated to cause the advance of the typewriter ca'rriage. v

Fig. 10 ,is a detail view, shown partly in section, ,of the control lever for adjusting the ribbonfeed and also illustrates in section the rollers which I provide the positive feed for the ribbon.

Fig. 11 is a detail view of a ribbon carrier shield which positions the ribbon at the printing point.

Fig. 12 is a plan view of the ribbon shield illustrated in Fig. 11.

Fig. 13 is a view showing a section on line .Fig. 18 is a top plan view of the removable feed disc and feed roll.

Fig. 19 is a bottom plan view of the feed disc and feed roll.

Referring more especially to Figs. 1 and 2, the

the key levers l are pivoted upon .a pivot bar. 2

which is mounted in the machine frame 4. These key levers extend rearwardly and the stop rods 5 .0 are positioned over each character key lever. Actuator bars 6 (one of which is shown in Fig. 2) operate actuators I which swing shuttle carrier 8 for the type segment 3 and also the stop arm III which strikes the upper end of the lifted stop rod 5 to position a type on the type shuttle 3 at the printing point, which type corresponds to the character key lever which was depressed.' The type shuttle is mounted to oscillate upon the anvil wheel II which sustains the printing blow when the printing operation occurs. This anvil wheel II is mounted upon a supporting shaft l2 which is solidly set in the machine frame 4. The anvil wheel H is adapted to be raised for case '5 shift and also for changing type shuttles so that a selected type shuttle may be set in effective position at the printing point. It is a characteristic of a typewriting machine of the kind illustrated that the type segments may be changed to provide various sizes and kinds of .type at the print: 6 ing point.

A type carriage is mounted for reciprocation past the printing point and is adapted to be moved one letter space for each actuation of a character key. The machine is provided with the usual space bar 14 which, when actuated, causes the carriage to move idly for one space for each actuation of the space bar. The carriage is provided with a basket l5 in which paper sheets are received when fed between the paper feed rolls I6 and I1. Suitable mechanism (not shown) is provided for the carriage feed. In the type of machine disclosed, the imprint on the paper is made by striking the paper and an interposed ribbon against the character positioned at the printing 20 point. This striking operation is performed by a hammer 'l8 and comprises a part of a hammer arm l9 which is mounted on a pivot 20 carried by the machine frame. All of the foregoing mecha* nism is well known in the typewriter art and, therefore, has not been described in specific detail. Reference may be made to patent to Trego No. 1,967,273, July 24, 1934, for further information regarding the details above outlined. 4

Referring. now more especially to Figs. 1, 2, and 16, the machine is provided with the usual ribbon feed mechanism comprising a pair of ribbon cups 2| and 22 through which extend shafts 24 and 25 that are adapted to be selectively driven by suitable mechanism to-feed the ribbon across be desired. The forward portion of the key. levers I and as- ,sociated mechanisms are protected by a front plate 32 which is mounted upon the machine frame and encloses the forward portion of the machine.

Referring now more especially to Figs. 1 and-16,

. a bracket 34 is attached to the left side of the machine frame -4 and carries a large stationary cup 35 which receives the supply roll 36 of narrow paper ribbon 31.. This'paper ribbon extends. over a guide roll 38 mounted on an arm 39 car- 55 ried by the stationary cup 35. The narro'w ribbon 31 extends through the ribbon shield 23 and to the'ribbon feed mechanism which is removably mounted in the ordinary ribbon cup 22. This narrow ribbon feed mechanism (see Figs. 10, 17, so

. 18, and 19) comprises a disc 40 in which is journalled a stub shaft 4| which is provided with a shoulder on the upper portion bearing against the disc 40 and an extension passing through the disc 40 with a retaining collar 42 mounted on the. 65

extension in order to mountthe stub shaft 4| in the disc! for rotation. The stub shaft carries on its upper end a knurled metal feed roller 44. The lower end of the stub shaft is provided with four circular pockets 45 each of .which is adapted to receive the driving pin 46"on collar 41 carried by the ribbon drive shaft 25. A bracket 49 is struck from the metal comprising the disc 40 and is bent over at the top to provide a bearing for the shaft 50 of a swinging arm 5|. This swing- -15 I universal bar 14 operates.

ing arm carries a shaft 52 on which is mounted a knurled idler feed roll 54. The shaft 52 extends downwardly through a slot 55 in the disc 49 and the lower end of the shaft is attached to a spring 58, the other end of which is secured to an anchor post 51 so that this spring normally urges the knurled feed roll 54 against the driven feed roll 44. The upper end of the idler feed roll 54 is provided with a flange which lies over the driven knurled feed roll 44 soas to comprise a guide for the narrow ribbon 31 which passes between these feed rolls 44 and 54. The shaft 52 is provided on its upper end with a thumb piece 59 by means of which the operator may swing the arm 5| to move the idler feed roll 54 away from the driven feed roll 44 for the insertion or removal of the narrow paper ribbon. As the paper ribbon leaves the feed rolls 44 and 54, it passes from the machine and may be destroyed as the ribbon is no longer useful for typewriting purposes in accordance with the present invention. The disc 40 is provided with a lug 50 which fits a slot II in the normal feed cup 22 to prevent the disc 40 from rotating. The disc 40 and the parts carried thereby are removable by lifting the same vertically from the feed cup 22 and then the ribbon mechanism is adapted to receive the usual textile wide ribbon spools in the cups 2| and 22.

The stationary cup 35 is provided with a hollow stud 62 upon which a wooden core 64 of the'supply roll 35 is adapted to rotate, and a cover plate 65 carries a thumb piece 86 which is provided with a split plug 61 that is adapted to be inserted in the opening 58 in the hollow stud 62 to retain the cover plate in position on the end of the hollow stud 92 to. retain the supply roll 36 in position within the stationary cup 35. The hollow stud 62 is slightly longer than the thickness of the supply roll 85 so as to avoid friction between the cover plate 65 and the supply roll 35 which rotates fgeely around the stud 62 when the ribbon is being f Referring more especially to Figs. 2, 3, 4, and 16, the drive mechanism for the ribbon feed will now be described. The hammer arm I9 is bifurcated at its inner end to provide a lower arm 69 to which the hammer spring 10 is attached so that when the hammer is set in cocked position,

the spring 18 is tensioned sufliciently to drive the hammer forwardly for printing operation as has been described when the hammer is released for printing. A universal bar 1| (Figs. 2,3, and 4) extends over the rear end of the key levers and also over the space bar arm 12 so that each time a character key or the space bar is actuated, the universal bar 1| is raised. This universal bar connects with the carriage mechanism which is not shown for the reason it is well known in the art. However, attention is directed to patent to Trego No. 1,933,570, November "I, 1933. A small universal bar 14 extends over the space bar arm 12 so that only the space bar operates the small universal bar 14, the reason for this being that it is important the hammer should not operate when the space bar is used and to this end the arm 15 (Figs. 2, 5, and 6) connected with the small universal bar 14 swings each time the small This arm 15 is provided on its lower end with an extension 18 (Figs. 3, 5, and 6) which moves beneath the shoulder 11 on the upper arm 18 of the bifurcated end of the hammer arm I 9, so that this extension 18 prevents movement of the hammer arm when the space bar is actuated.

The effective operation of the extension 16 JI'he above mechanism comprising the small 5 universal bar 14 and the arm 15 is a part of the ribbon feed control in that a pin 19 carried on the side of the arm 15 is constructed to contact a swinging arm loosely mountedupon a ribbon driving shaft 8|. so as to rotate around this 10.

driving shaft (Figs. 4, 5, 6, and 16). This arm arm carries a lift arm 82 which extends outwardly beyond the operative face of a ratchet wheel 84 which is fixedly mounted on the ribbon driving shaft 8| and is adapted when actuated 5 to rotate the said driving shaft. An extension 85 is also provided on the swinging 'arm 80. A spring 86 normally urges the arm 80, lift cam 82 and extension 85 in a counter-clockwise direction as shown in Figs. 5 to 9 inclusive. The move- 20 mentof these parts under the operation of the spring 86 is checked either by the arm 80 contacting with the pin 19 as shown in Fig. 5 or with the lower end of the arm 80 contacting with a stop dog 81 on a control lever 88, as shown in Fig. 5

6. This control lever 88 (Figs. 3, 4, and 16) comprises a main lever 89 which carries a relief arm 90 that extends upwardly to be engaged by a pin 9| on a setting handle shaft 92 which is under control of a setting handle 94 which extends 30 through a dial plate 95 (Fig. 1) that is provided with notches 96. This setting handle 94 and setting lever shaft are adapted to regulate the carriage feed with reference to the width of character space movements of thecarriage, and the 5 dial plate 95 is marked with numerals "10, 12 and 14. These numerals mean that when the setting lever 94 has been moved and positioned in a notch 98 that the carriage movement for each character space operation will be respectively one- 40 tenth, one-twelfth, or one-fourteenth of an inch dependent upon the particular notch in which the setting handle is positioned.

Trego No. 1,918,299, July 18, 1933) As has previously been explained, it is desir- 5 able for the ribbon feed to bear a definite relation to the carriage feed, and, therefore, the setting handle 94 which controls the setting of the carriage feed also controls the ribbon feed as will now be explained. When the setting handle 94 50 is operated to shift the handle shaft 92 longitudinally to change the carriage feed, the pin 9| acts upon the relief arm end of the control lever 88. This relief arm 90 is held against the pin 9| by a spring 91 (Fig. 16). The operation of 55 the pin 9| on the relief arm 90 is to swing the control lever 88 on the pivot 98 which is mounted on the underneath portion of the machine frame. The swinging of the control lever 88 changes the position of the stop dog 81 relative to the exteno0 sion 85 and this controls the position of the lift cam 82 relatively to the ratchet wheel 84. As shown in Fig. 5, the setting handle 94 is set in the "10 notch 99 of the dial plate 95. This permits the control lever 88 to swing on its axis 65 sufliciently to remove the stop dog 81 from contacting with the extension 85 on the arm 80 so that the spring 86 operates to swing the arm 80 until it contacts with the pin 9|. Fig. 6 shows the relation of the parts when the setting handle 70 with a lever stop 99 (Fig. 16) This has advanced 75 (See patent to the stop dog 81 as shown in Fig. 6 to swing the swinging arm 88 clockwise and to advance the lift cam 82 relative to the ratchet wheel 84. Since there is little difference between the carriage feed when the setting handle is moved from notch "12 to notch "14 in the present instance,

it has been deemed desirable to make'no further setting handle 84 is moved from the notch 12" to the notch "14 of the dial plate 95, the relief arm 88 swings upon its pivot and stresses the spring I88 but since the main lever 89 is in engagement .with the lever stop 99, the stop dog 81 has not changed its position.

A driving pawl I82 is pivoted on the upper arm 18 (Figs. to 8 and 16) and is urged in the direction of the ratchet wheel 84 by a helical spring I84. When the lift cam 82 is positioned as shown in Figs. 5 and 8, when the setting lever is in the notch the driving pawl I82 is in engagement with the teeth of the ratchet wheel 84. When the hammer arm I8 is operated to cook the hammer, the driving pawl I82 is raised, as is indicated in dotted lines in Figs. 5 to 9 inclusive. It, therefore, will be noted that when the parts are set as illustrated in Figs. 5 and 8, the driving pawl I82 will rotate the ratchet wheel 84 three teeth when the driving pawl is lifted and consequently will rotate the ribbon driving shaft 8| a corresponding amount. When the parts are in the position illustrated in Figs. 6 and 7, the

lift cam 82 has raised the end of the driving pawl I82 from the teeth ofvthe ratchet wheel, when the parts are in stationary normal position. Therefore, when the driving pawl I82 is lifted,

it is effective to move the ratchet wheel two teeth and this, therefore, correspondingly shortens the angular rotation of the ribbon driving shaft and thereby shortens the ribbon feed. When the space bar I4 is operated, the forward end 12 of the spacebar arm raises the small universal space bar I4 and this causes the pin I8 on the arm 18 to engage the S-shaped cam 'face 83 on the swinging arm 88 so that when the parts cometo rest, the swinging arm 88 has reached a substantially vertical position as illustrated in Fig. 9. This positions the lift cam 82 beneath the driving pawl I82 so that as soon as a slight pressure is relieved from the space bar sufllcient to permit the hammer to be cooked and the pawl m. to be actuated, it will be observed that the complete stroke of the pawl I82 is on the face 85 l of the lift cam- 82, and, therefore, is ineffective to rotate the ribbon shaft 8I so that no ribbon feed occurs when the space bar is operated. A holding dog I88 ,(Figs. 5, 6, and 16) comprises a flatspring secured to the machine frame and V with its free end bearing against the teeth of the ratchet wheel 84. This prevents retrograde movement of the ratchet wheel and holds the parts in position to which they have been moved by the "last operatlonof the'driving pawl I82.

at a time and to shift the engagement from one pair of gears and tension to the other pair of gears and tension to reverse the ribbon when wide textile ribbon is used in the normal operation of the machine as is well known in the patent to TregoNo. 1,930,068, October 10, 1933. This reversing-operation is not effective while the narrow ribbon attachment is being used. From the foregoing, it will be observed that angular rotative movements imparted to the ribbon driving shaft 8| will be communicated to the shaft 25 and hence to the knurled metal feed roller 44, carried by the disc 48, to impart movement thereto to feed the narrow ribbon.

The ribbon shield 26 previously referred to comprises a thin flexible sheet of metal I I8 which as previously explained is mounted upon arms 21 and 28. The forward ends of these arms 21 and 28 are each provided with uprights land I I2. Each end of the shield 28 is folded backwardly upon itself to provide pockets H4 and lit to receive the-uprights III and H2 when the ribbon shield is in position for operation. This ribbon shield is provided with two printing opens ings H8 and I I! through whichprin'ting characters on the type shuttle8 are exposed for printing operation. The lower opening II! in the present shield is intended to be uncovered. that is, there is no ribbon which extends over this opening, and consequently, the opening III may be used for making stencils. The ribbon shield is "provided with a pair of flat tubular guides H8 and H9 through which is provided a very thin opening having a width and height substantially corresponding to the thickness andwldth of the paper ribbon. The ends I28 and I2I of the flat tubular guides H8 and III! are bent outwardly to comprise guide wings to guide the ribbon through these flat tubular guides without interfering with orscraping the pigmentation carried thereon. .These narrow fiat tubular guides are of substantial importance in the operation of the device. The ribbon shield being extremely flexible and very thin, does not in any way interfere with the printing operations but securely holds the narrow flat ribbon in position for operation when'the thin paper ribbon is being utilized as has been explained. 4

When the narrow thin paper ribbon passes time the ribbon supply is exhausted. This nar-" row ribbon is of a maximum width which is substantially the width of the maximum size ofprinting characters adapted for use in the machine so that the entire ribbon face is available for printing operations. The ribbon shield 28 being provided with the two openings H8 and II! makes this shield particularly useful with a machine of this character in that the narrow ribbon covers only that portion of the shield in whichis located the printing opening IIB thereby leaving the opening II I at all times available'for cutting stencils without any manipulation of the ribbon mechanism other than the raising of the ribbon shield sufliciently to make the opening II'I available. This makes the machine quickly convertible from ,use as a printing machine to a stencil cutting machine.

Another advantage of the flat tubular guides H8 and II! is that these guides being very narrow and smooth and f0 med of flexible metal donot have any tendency to flake the pigmented flexible metal having tubular guide tubes on each coating and feed the ribbon in an eflicient, accurate, ard satisfactory manner.

The narrow paper ribbon comprising a part of this invention is preferably'a strip of material known in the art as carbon paper. This strip is preferably coated on one side only. Thus there is no danger of the pigment material collecting on the type, and, therefore, each type impression is clear and sharp. Since the pigment coating is uniform and the strip is used but once, each printing character is of uniform density and the typewritten sheet is' admirably adapted for reproduction by lithography.- The machine is constructed to use rolls of this narrow ribbon comprising substantially twelve hundred feet of ribbon strip which is approximately one-quarter of ,an inch in width.

Since the paper strip is used but once, it should I be conserved in use, and, therefore, the feed of change the ribbon strip feed when the carriage a machine for each feed is changed. Since no ribbon strip feed is necessary when the carriage moves under control of the space control, the ribbon strip feed is not effective when the space bar is operated.

While the present invention is preferably an attachment which is auxiliary to the normal ribbon feed, it may be constructed as a main ribbon feed structure.

What we claim is:

1. In a machine of the class described, the combination of printing type, means to present selected printed type at a printing point, means toguide a narrow ribbon paper strip having pigmentation thereon to present the same in effective position relative to said printing type, means to impress printing type through said ribbon upon an impression sheet, means to feed said narrow ribbon strip definite predetermined intervals for each operation of the machine, carriage feed means, and means to change both said carriage feed and said ribbon feed from one definite predetermined feed to another definite predetermined feed.

2. In a machine of the character described, the combination of printing type adapted to be presented at a printing point, a narrow ribbon strip carrying pigmentation, ribbon guide means adapted to guide a narrow paper ribbon and to present a portion of said ribbon strip in effective position relative to said printing typ Said ribbon guide means comprising a shield of thin side of said printing point, wing guides on the outer edges of said tubular guides to guide the paper ribbon through the flat tubular guides without interfering with the pigmentation there- Bn,.me'ans to cause an impression to be made on an impression sheet through said narrow. strip ribbon, and means to feed said ribbon out of said operation of said impression means only, whereby'said ribbon may have but a singleuse in said machine. n I

'3. In a machine of the class described, a narrow paper -ribbon'having' one' side coated with pigmentation and the other side non-pigmentized, printing type, said paper ribbon being substantially as wide asthe largest printing type is high, means to feed Saidflbbon past said printing type with the non-pigmentized side of the ribbon toward said printing type, and a flexible metal ribbon shieidfadiacent the printing point ing means operative at a for said type, a pair of tubular ribbon guides carried by said shield on each side of said printing point, guide wings on the outer edges of said tubular ribbon guides, said ribbon shield being adapted to withhold said ribbon from contacting with an impression sheet during a printing operation except that portion of the ribbonover the type which is effective at the printing point,

said shield being, constructed to present the mid portion of 'said paper ribbon to said printing type. f

4. In a machine of the class described, printing means operative at a printing point, means to support a roll of narrow paper ribbon adapted for a single use in said machine, means to feed said ribbon step by step past said printing point, a carriage to support impression material, carriage feed means to feed said carriage step by step past said printing pointf'control means to set the step by step movement of the carriage according to the width of printing characters in use, and means operated by said control means to set the step by step feed. of the ribbon according to the step by stepsetting of said carriage feed.

5. In a machine of the class described, printing means operative at a printing point, means to support a roll of narrow paper ribbon, means to feed said ribbon past said printing point after each printing operation, a carriage to move impression material past said printing point, car- I riage feed means to feed the carriage step by step past the printing point, control means to set the step by step movement of, the carriage according to the width of printing characters in use, and means to set the ribbon feed movement according to the carriage feed.

6. In a machine of the class described, printprinting point, means to support a roll of narrow ribbon, means to feed said ribbon one printing character space for each printing operation only of the machine, a carriage to support a sheet of impression material, carriage feeding means to move said carriage one printing character space for each printing operation, and means toydisable said ribbon feed when said carriage is-moved for spacing between hammer adapted to strike an impression sheet against said character at the printing point,

means to-support a portion of a narrow paper,

ribbon at the printing point, means to feed said narrow paper ribbon when said printing hammer is rendered effective to strike a printing blow, a

carriage to support'said impression sheet, means to feed said carrlagestep by step past the printing point, a space bar and connections to cause said carriage to move for word spacing, and 1 means to disable said ribbon feed when said space bar is operated.

8. In a machine of the class described, arib bon, means to guide said ribbon past a printing point, a readily removable. type font having.

printing type characters for use at the printing point, said font being adapted to be removed so as to be replaced by another font, the printing characters of which are of a different width from the corresponding characters of the first Y mentioned font, means. toamake printing impressions at the printing point from the printing type of the font in use at the printing point and adJustable feeding means for said ribbon to feed the ribbon step by step past said printing point by amounts according to the printing type of the font in use at the printing point, and means having a portion thereof exterior. of the machine for adjusting the amount of the feed of said adjustable feeding means.

9. An attachment to replace one of the normal ribbon spools of a typewriter, said attachment being adapted to feed a ribbon and comprising a unit having a base plate, a feed roller mounted for rotation on said base plate; a pivoted arm mounted on said base plate, said arm carrying an idler roller, a spring adapted to urge the free end of said arm toward said feed roller to cause said idler roller to be spring pressed toward said feed roller, means to operatively couple said feed v roller with the ribbon spool drive shaft of said typewriter, and means on said base plate adapted to cooperate with a, fixed portion of said typewriter to prevent the rotation of said base plate. 10

RALPH C. COXHEAD. 

